1. Technical Field
The present invention relates to a data access method, and more particularly, relates to a data access method, a memory storage apparatus and a memory control circuit unit for a rewritable non-volatile memory module.
2. Description of Related Art
The growth of digital cameras, mobile phones, and MP3 players has been expanded rapidly in recent years. Consequently, the consumers' demand for storage media has increased tremendously. A rewritable non-volatile memory is one of the most adaptable memories for portable electronic products such as notebook computers due to its data non-volatility, low power consumption, small volume, non-mechanical structure and high read/write speed. A solid state drive is a storage apparatus which utilizes a flash memory as its storage medium. For these reasons, the flash memory has become an import part of the electronic industries.
Data stored in the rewritable non-volatile memory may generate error bits due various factors (e.g., current leakage, programming failures and damages on the memory cell, and etc.). Therefore, an error checking and correcting circuit is generally disposed in a memory storage system to generate an error checking and correcting code for the stored data in order to ensure data correctness. However, when the number of the error bits exceeds the number of the error bits that can be detected and corrected by the error checking and correcting circuit, the data containing the error bits cannot be corrected to thereby cause loss of data.
Accordingly, how to correct more of the error bits and ensure the data correctness is one of the major subjects in the industry.
Nothing herein should be construed as an admission of knowledge in the prior art of any portion of the present invention. Furthermore, citation or identification of any document in this application is not an admission that such document is available as prior art to the present invention, or that any reference forms a part of the common general knowledge in the art.